Economy · Markets & Power

Corporate Concentration & Antitrust

1890— present

America broke up the trusts in 1890 — and a century later, a handful of firms dominate industry after industry again.

The Sherman Antitrust Act of 1890 was a response to the Gilded Age trusts; the century since has swung between vigorous trust-busting and hands-off tolerance, and by many measures market concentration has climbed back toward early-1900s levels across tech, airlines, meatpacking, and more. This traces the long arc of antitrust enforcement and concentration, what the laws actually do, how the dominant legal philosophy shifted, and why a new bipartisan appetite for enforcement has emerged.

Industries more concentrated since 1997

2 in 3

of ~900 U.S. industries (Census / Grullon et al.)

DOJ monopolization cases: 1970s → 1980–97

221 → 22

Sherman §2 / vertical suits (BFI, U. Chicago)

Average corporate markup, 1980 → 2016

61%

over cost, up from 21% (De Loecker et al.)

Google share of the search market

~90%

plus 91% ad-server share (U.S. v. Google)

Mergers reported to the agencies, FY2024

2,031

~1 in 4 valued over $1 billion (FTC HSR)

Antitrust timeline · 1890 — present

Hover any milestone for context.

StatuteCourt rulingDoctrine shiftEnforcement

Shaded band: the "consumer welfare" era (1977–2016), when the courts and agencies read antitrust narrowly and concentration climbed.

What antitrust is for

Antitrust law is the government's tool for keeping markets competitive. It does three main jobs: it stops firms from colluding (price-fixing and cartels), it stops a dominant firm from monopolizing a market through exclusionary conduct, and it reviews mergers before they close to block the ones that would substantially lessen competition.

It grew out of the Gilded Age. In the 1880s a handful of "trusts" — Standard Oil, sugar, railroads, steel — had swallowed whole industries. The Sherman Antitrust Act of 1890 was Congress's answer, passed almost unanimously. The century since has swung between vigorous trust-busting and hands-off tolerance.

Who enforces it

The DOJ Antitrust Division. The only enforcer with criminal power — cartels are felonies. It also brings civil monopolization and merger suits in federal court.
The Federal Trade Commission. An independent five-member agency with its own in-house court and a broader "unfair methods of competition" mandate. It shares merger review with the DOJ.
State AGs, courts & private suits. States enforce both federal and their own antitrust laws; most large cases are co-led by state coalitions. Private parties can sue for treble (triple) damages.

The core statutes

All of U.S. antitrust runs on a few short, deliberately vague laws. Their meaning is filled in by the courts — which is why the same words have produced wildly different regimes.

Sherman Act (1890)

The backbone. Section 1 bans agreements that restrain trade — price-fixing, bid-rigging, market-allocation cartels (the per-se crimes). Section 2 bans monopolization: acquiring or keeping monopoly power through exclusionary conduct, not merit. Criminal violations carry prison time.

Clayton Act (1914)

Targets conduct "in its incipiency," before a full monopoly forms. Section 7 — the merger law — bars deals whose effect "may be substantially to lessen competition." Also reaches tying, exclusive dealing, and interlocking directorates. Enforced civilly, by the DOJ, FTC, states, and private plaintiffs.

FTC Act (1914)

Created the Federal Trade Commission and gave it Section 5, banning "unfair methods of competition" — broader than the Sherman Act and enforced through the FTC's own administrative process. The FTC shares merger and monopoly enforcement with the DOJ.

Hart-Scott-Rodino Act (1976)

The plumbing of modern merger review. Deals above a size threshold (about $120M in 2024) must be reported to the agencies and wait before closing, giving regulators a chance to investigate — or sue to block — before the merger is consummated.